SANTA ANA, Calif. (KABC) -- The Orange County District Attorney is fighting back against claims his office isn't doing enough to respond to the sheriff's department's latest scandal involving deputies allegedly mishandling evidence.

"I want the public to have confidence that I've insisted on a process that's absolutely fair, that I'm overseeing it myself personally, and we will make sure that not one person suffered an unlawful conviction because of a failure to book evidence by the Orange County Sheriff's Department," DA Todd Spitzer said.

The claims come from Assistant Public Defender Scott Sanders. He has a felony grand theft case that could be directly affected by a deputy accused of mishandling evidence in 74 cases. That deputy is one of 16 who were investigated by the sheriff's department after its internal audit.

"There's really no question this is this the tip of the iceberg. If you said there was just a few things that were problematic and we find out with one case there's 74 cases with missing evidence, I think we should all reasonably expect that there's thousands of affected and tainted cases," Sanders said.

He added that the deputy is in the process of being fired, but he's outraged the DA's office did not press criminal charges.

"If a regular citizen had 74 cases in which they filed false reports, they'd be prosecuted as quickly as you can imagine," Sanders said. "Here, nothing's happening to a person who takes a sworn oath in uniform, it makes no sense. It's not fair."

But the District Attorney says criminal investigations are still open.

"That is not over. We are presently looking at all of those cases that have been submitted by the sheriff to determine if those deputies were engaged in criminal conduct," Spitzer said.

The sheriff's department released a statement, saying in part: "This is an issue of policy that we identified, we addressed, affected parties were notified, and we have remedied with safeguards to ensure this does not happen in the future."

To ensure justice in the cases that might be affected by deputies involved, the DA tells Eyewitness News that evidence in about 22,000 cases will now be hand searched.

"I've assigned DA investigators to look over the shoulders of those sheriff personnel while they're conducting that investigation to make sure we are independently satisfied with this new audit that has been prescribed by me," Spitzer said.

He added his office has also notified defense attorneys in 560 cases of possible issues with evidence.

"Not one criminal defense attorney, including the public defender's office, has asked for a re-review of any of those 560 cases, or have asked us to dismiss charges or filed any motions in any of those 560 cases," Spitzer said.

The district attorney also said he inherited a lot of baggage since he took office just over a year ago. He says he's committed to turning things around.

The public defender insists he isn't satisfied with what he sees so far.